<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            display: flex;
            justify-content: left;
            width: 260px;
            height: 30px;
            line-height: 30px;
            border: 1px solid #ccc;
            border-radius: 10px;
            margin-left: 20px;
        }

        input {
            border: none;
            outline: none;
            padding-left: 10px;
        }

        select {
            margin-left: 15px;
            border: none;
        }
    </style>
</head>

<body>
    <div>
        <select name="" id="number">
            <option value="">+86</option>
        </select>
        <span>|</span>
        <input type="text">
    </div>
</body>

</html>